[PATCH] drm/i915/dp: allow configuring eDP panel fitting scaling mode

[Yuly Novikov]

LVDS allowed changing panel fitting scaling mode, while eDP didn't.
Copied relevant code from LVDS to eDP.
This also changes default mode on eDP to ascpect ratio preserving scaling.

Signed-off-by: Yuly Novikov <ynovikov at chromium.org>
---
 drivers/gpu/drm/i915/intel_dp.c  |   33 ++++++++++++++++++++++++++++++---
 drivers/gpu/drm/i915/intel_drv.h |    1 +
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 368ed8e..a65546e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -685,7 +685,7 @@ intel_dp_mode_fixup(struct drm_encoder *encoder,

        if (is_edp(intel_dp) && intel_dp->panel_fixed_mode) {
                intel_fixed_panel_mode(intel_dp->panel_fixed_mode, 
adjusted_mode);
-               intel_pch_panel_fitting(dev, DRM_MODE_SCALE_FULLSCREEN,
+               intel_pch_panel_fitting(dev, intel_dp->fitting_mode,
                                        mode, adjusted_mode);
        }

@@ -2358,6 +2358,22 @@ intel_dp_set_property(struct drm_connector *connector,
                goto done;
        }

+       if (is_edp(intel_dp) &&
+               property == connector->dev->mode_config.scaling_mode_property) {
+               if (val == DRM_MODE_SCALE_NONE) {
+                       DRM_DEBUG_KMS("no scaling not supported\n");
+                       return -EINVAL;
+               }
+
+               if (intel_dp->fitting_mode == val) {
+                       /* the eDP scaling property is not changed */
+                       return 0;
+               }
+               intel_dp->fitting_mode = val;
+
+               goto done;
+       }
+
        return -EINVAL;

 done:
@@ -2469,10 +2485,21 @@ bool intel_dpd_is_edp(struct drm_device *dev)
 }

 static void
-intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector 
*connector)
+intel_dp_add_properties(struct drm_device *dev,
+                       struct intel_dp *intel_dp,
+                       struct drm_connector *connector)
 {
        intel_attach_force_audio_property(connector);
        intel_attach_broadcast_rgb_property(connector);
+
+       if (is_edp(intel_dp)) {
+               drm_mode_create_scaling_mode_property(dev);
+               drm_connector_attach_property(
+                       connector,
+                       dev->mode_config.scaling_mode_property,
+                       DRM_MODE_SCALE_ASPECT);
+               intel_dp->fitting_mode = DRM_MODE_SCALE_ASPECT;
+       }
 }

 void
@@ -2665,7 +2692,7 @@ intel_dp_init(struct drm_device *dev, int output_reg, 
enum port port)
                intel_panel_setup_backlight(dev);
        }

-       intel_dp_add_properties(intel_dp, connector);
+       intel_dp_add_properties(dev, intel_dp, connector);

        /* For G4X desktop chip, PEG_BAND_GAP_DATA 3:0 must first be written
         * 0xd.  Failure to do so will result in spurious interrupts being
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fe71425..da50cd4 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -358,6 +358,7 @@ struct intel_dp {
        int backlight_on_delay;
        int backlight_off_delay;
        struct drm_display_mode *panel_fixed_mode;  /* for eDP */
+       int fitting_mode;  /* for eDP */
        struct delayed_work panel_vdd_work;
        bool want_panel_vdd;
        struct edid *edid; /* cached EDID for eDP */
-- 
1.7.7.3